The goals of our studies are to characterize the immunobiology of epidermal cells grown in culture. We have developed a method for growing human epidermal cells in culture which has recently been reported (1). As the transplantation of sheets of cultured human epidermal cells has obvious clinical importance, we wish to develop methods to culture guinea pig epidermal cells and their use as autologous and allogeneic grafts. We also wish to characterize cultured human epidermal cells for their potential use as allografts. We will define the optimal conditions for the growth in vitro of differentiated sheets of guinea pig epidermal cells suitable for use as grafts. We will assess the efficacy of these methods by measuring epidermal cell growth and differentiation products. We will define the conditions necessary to remove epidermal cells from culture vessels, and the conditions needed to store cultured epidermal cells for future use. We will transplant cultured guinea pig epidermal cells onto the donor animal and onto allogeneic animals. We will determine the origin of re-epithelized grafted and karyotyping healed epidermis. We will examine the effect of growth in vitro on the ability of human epidermal cells to express antigens related to allograft rejection.